Add Wait* API to ActionRunner to wrap over WaitAction.

tools/perf/page_sets/mse_cases.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 # pylint: disable=W0401,W0614
 from telemetry.page.actions.all_page_actions import *
 from telemetry.page import page as page_module
 from telemetry.page import page_set as page_set_module
 
 
 class MseCasesPage(page_module.Page):
 
   def __init__(self, url, page_set):
     super(MseCasesPage, self).__init__(url=url, page_set=page_set)
 
   def RunNavigateSteps(self, action_runner):
     action_runner.NavigateToPage(self)
-    action_runner.RunAction(WaitAction(
-      {
-        'javascript': 'window.__testDone == true'
-      }))
+    action_runner.WaitForJavaScriptCondition('window.__testDone == true')
 
 
 class MseCasesPageSet(page_set_module.PageSet):
 
   """ Media source extensions perf benchmark """
 
   def __init__(self):
     super(MseCasesPageSet, self).__init__()
 
     urls_list = [
@@ skipping 12 matching lines @@
       'file://mse_cases/startup_test.html?testType=A',
       'file://mse_cases/startup_test.html?testType=A&useAppendStream=true',
       # pylint: disable=C0301
       'file://mse_cases/startup_test.html?testType=A&doNotWaitForBodyOnLoad=true',
       # pylint: disable=C0301
       'file://mse_cases/startup_test.html?testType=A&useAppendStream=true&doNotWaitForBodyOnLoad=true',
     ]
 
     for url in urls_list:
       self.AddPage(MseCasesPage(url, self))